1. Field of the Invention
The present invention relates to an alkaline battery separator, i.e., a separator for an alkaline battery, and a process for producing the same.
2. Description of the Related Art
In an alkaline battery, a separator is used between a positive electrode and a negative electrode to separate them and to prevent a short circuit therebetween, and further, to hold an electrolyte thereon and enable a smooth electromotive reaction.
Recently, a space allotted for the battery has become smaller in electronic equipment, due to the need for miniaturization and weight-saving. Nevertheless, the performance requirement for such a smaller battery is the same as or higher than that for a conventional battery, and therefore, it is necessary to increase the capacity of the battery, and to increase the amounts of active materials in the electrodes. Thus, a volume allotted in the battery for the separator must be reduced, and a thickness of the separator must be made thinner. However, if a conventional separator is simply thinned, the capacity thereof for holding an electrolyte (i.e., the electrolyte-holding capacity) is lowered, and a dispersibility of fibers is liable to become lower. Therefore, Japanese Unexamined Patent Publication (Kokai) No. 7-29561 and Japanese Unexamined Patent Publication (Kokai) No. 8-138645, for example, disclose that the electrolyte-holding capacity and the dispersibility of fibers can be enhanced by forming a fiber web by a wet-laid method, using dividable composite fibers capable of producing fine fibers having a linear density of 60 .mu.g/m or less. The separators disclosed in these Japanese Publications have an advantageous electrolyte-holding capacity and dispersibility of fibers, but are liable to be broken by the tension generated during a step of assembling electrodes during battery production. Further, an electrode flash and an active material may break and penetrate the separator, to thus cause a short circuit between the electrodes, and therefore, the yield is poor. Further, the separators have low tear-strength and low bending resistance which also lowers the yield.